The lead defendants in the nation’s first female genital mutilation case moved late Wednesday to dismiss the most serious count against them, a sex charge punishable by up to life in federal prison.

Dr. Jumana Nagarwala and Dr. Fakhruddin Attar want U.S. District Judge Bernard Friedman to dismiss a conspiracy charge alleging they transported minors to Metro Detroit with the intent to engage in criminal sexual activity, according to a court filing.

The pair’s alleged conduct does not qualify as sexual activity because the doctors did not intentionally touch the girls’ genitalia for gratification or to abuse, humiliate or degrade anyone, their lawyers argued. The criminal charge also is unconstitutionally vague, they added.